• Floodplains are species-rich but endangered habitats. With rapidly changing climatic conditions, their situation will become even more precarious in the future.
• A study by the WSL shows that today's protected areas will not suffice and additional areas should be included in conservation efforts.
• Auenschutzpark Aargau is an example for successful planning and conservation efforts.

Climate change impacts habitats in and around water most severely. They are threatened by an increase of droughts and declining water levels, but also by increasingly extreme flooding. Thus, areas that are protected today will no longer be suitable for floodplain species in a couple of years. However, new regions will emerge along the river catchment where, thanks to better conditions, new floodplains can develop.

To understand where the valuable floodplain habitats might be located in the future, the researchers used several models. Applying an ecological model, they mapped the projected distribution of different species based on factors such as, for example for plants, temperature, slope of the embankment or soil conditions. Using a hydrodynamic model, they calculated other factors affecting riverscapes, such as potential zones of flooding and erosion. By combining the two models, the researchers were able to predict where floodplain species might occur in the future.

The analyses show that, in the future, most of the current protected areas will no longer be as effective as they need to be. For example, many of them will become too dry or their banks will erode. They are also too small and not sufficiently connected longitudinally. This means that animals, plants and fungi cannot colonize new habitats because these are too far away or do not exist.

According to the researchers, it is imperative to protect existing floodplains to preserve as much habitat and biodiversity as possible. “Given the losses, every single floodplain matters,” says WSL ecologist Sabine Fink. She emphasises that the entire catchment areas of rivers need to be longitudinally connected. This is particularly crucial in densely populated Switzerland, as it would be unrealistic to restore rivers to their original state along their entire catchment. According to the ecologist, effective planning must also prioritize long-term considerations. “Not only must current floodplain areas be protected, but planning should also already include areas that may become floodplains in the near or far future. The aim is to connect these habitats with currently protected floodplain areas and thus preserve these threatened ecosystems.”